Steroid 21-aldehydes



STERQID ZI-ALDEHYDE'S LeWis H. Sarett, Princeton, NIL, assignor to Merck &

C0., lino, Rahway, N. 3., a corporation of Ne'w'lersey "No Drawing. Application February E1, 1955 Serial No. 487,714

Claims. (Cl. 260-39745) This invention is concerned generally with novel steroid compounds and with processes of preparing the same. More particularly, it relates to 2l-aldehyde derivatives of A -3,1l,20-triketo-17a,2l-dihydroxy-pregnadiene and related compounds, and the process of making these A -3,20 diketo ll oxygenated 17 hydroxy-pregnadiene ZI-aldehyde compounds. These new aldehydes possess cortisone-activity, but difier from cortisone in being'substantially free of undesired side eflects such as sodium or water-retention action.

These novel A 3,20 diketo ll oxygenated 17- hydroxy-pregnadiene 21-aldehyde compounds, subject of 'the present invention, may be chemically represented as follows:

CHO

alcohol grouping to an aldehyde to produce the retrocortin 21-aldehyde compound.

The A -3,20-diketo-l1-oxygenated-17-hydroxy-pregnadiene compounds having a free 2l-alcohol grouping which are ordinarily employed as starting materials in the hereinabove-mentioned procedure include A -3,1 1,20- triketo l7c:,2l dihydroxy pregnadiene, A 3,20- diketo 115,17 halo-3,11,20- .to 1%.,21 dihydroxy-pregnadiene such as n -9a-fiuoro-3J LZO-triketo-l7ct,2l-dihydroxy-pregnadiene, A -9a-Chl0IO3,lLZG-trlkfiit) l7a,2l dihydroxypregnadiene, A -9-haio-3,20 diketo llfi,l7u,2l trihydroxy pregnadiene compounds such as A 9c: chloro- 3,2O diketo ll ,8,l7a,2l trihydroxy pre nadiene, A Qa-fiuoro 3,29 diketo 11B,l7oc,21 trihydroxy-pregnadiene, and the like. The reaction between these A 3,20 diketo l1 oxygenated l7 hydroxy-pregnadiene 21 -free alcohol compounds and the cupric acetate is conveniently conducted by reacting one equivalent or" the A 3,20 diketo ll oxygenated l7 hydroxy-pregnadiene 21-alcohol compound with about two equivalents of the cupric acetate, since the use of a slight excess of the latter, i. e. about 2.1 to 2.2 equivalents thereof, results in the obtainrnent of maximal yields of the A 3,20 diketo 11 oxygenated 17 hydroxy pregnadiene Zl-aldehyde compounds. The reaction beactants together in a polar solvent as for example water,

21 trihydroxy pregnadiene, A 9 i keto'l 1,6,17e-

ice

lower alkanols, lower dialkyl ketones, dioxane, tetrahydrofuran, and the like. Since maximum yields are usually secured when the reaction is formed at an acid pH, it is preferred to add a small amount of an acid such as acetic acid to the reaction mixture. The reaction may be carried out at room temperature but it is preferred to conduct the oxidation at the reflux temperature of the solvent mixture employed; when methanol is used as the solvent, and the reaction is carried out under reflux, the reaction is ordinarily complete within an hour.

The A -3,20-diketo-ll-oxygenated-17-hydroxy-pregnadiene 2l-aldehyde compound is ordinarily recovered by filtering the reaction mixture to remove by-product cuprous oxide and adding water to the filtered solution, whereupon the A -3,2O-diketo-l1-oxygenated-17-hydroxy-pregnadiene ZI-aldehyde compound precipitates, and is recovered by filtration.

The A -3,2O-diketo-1l-oxygenated-l7-hydroxy-pregnadiene 2l-aldehyde compounds obtained in accordance with this procedure include iQ -ll l,20-triketo-l7o;-hydroxy-pregnadiene 21-aldehyde, A -3,20-diketo-115,170;- dihydroxy-pregnadierie 21-aldehyde, A -9-halo-3,11,20- triketo-l7ahydroxy-pregnadiene 2.1-aldehyde, A cfluoro-3 l l ,ZO-triketo-l 7a-hydroxy-pregnadiene 21-aldel :5 9.t-chloro-3.ii,2i ;il;etol7a-hydroxy-pregnadeh' de, -9-halo-3,20-diketo-1 113,17wtlll3jy-pregn e 2l-aldehyde, AB -9a fiuoro 3,2 diydrox -pregnadiene ZI-aldehyde, A -9w chloro-3,20-diiteto l1 8,l7ot dihydroxy-pregnadiene 21- aidehyde, and the like.

The following examples illustrate methods of carrying out the-present invention, but it is to be understood that these examples are given for purposes of illustration and not of limitation.

Example 1 To a solution of 200 mg. of A -3,1l,20-triketo-l7,2ldihydroxy-pregnadiene in 10 ml. of methanol containing 3 drops of glacial acetic acid is added a solution of 240 mg. of cupric acetate hydrate in 30 ml. of methanol. The resulting mixture is heated under reflux for a period of about 45 minutes, and the reaction mixture is filtered thereby removing by-product cuprous oxide formed during the reaction. About 40 ml. of water is added to the filtered methanol reaction solution, and the resulting mixture is evaporated under reduced pressure to a volume of about 10 ml. The crystalline material which separates from the solution is recovered by filtration and dried to give A -3,11,ZO-triketo-17-hydroxy-pregnadiene 21-aldehyde.

The retrocortin utilized as starting material in this example can be prepared as follows: a solution containing 39.6 g. of bromine in 306 cc. of acetic acid is added to a solution containing g. of 3,11,20-t1'ik6i0-17whY- droxy2l-acetoxy-pregnane dissolved in 1500 cc. of acetic acid. When the reaction is substantially complete, the solution is immediately poured into water, and the resulting suspension is extracted with chloroform. The chloroform extract is washed with water, evaporated to dryness, and the residual material crystallized from acetone-ether to give as a substantially pure crystalline product the 4- bromo 3,11,20 triketo 17a hydroxy 21 acetcxypregnane.

The mother liquor from this crystallization procedure is dissolved in benzene and chromatographed over acidwashed alumina, and the chromatogram eluted with mixtures of ether and chloroform. The eluate is evaporated to dryness, and the residual crystalline material is recrystallized from ethyl acetate to give 2-bromc-3,ll,20- triketo-lh-hydroxy Zl-acetoxy-pregnane. A solution of 393 mg. of this 2-bromo-3,l1,20-triketo-17u-hydroxy-2lacetoxy-pregnane in 5 ml. of'collidine is heated for one hour under reflux, and the collidine is evaporated in vacuo. The residual material is dissolved in chloroform, and the chloroform extract is washed with dilute aqueous hydrochloric acid, then with water, dried and evaporated in vacuo to dryness. The residual material is recrystallized from ethyl acetate to give substantially pure A 3,11,20 triketo 17oz hydroxy 21 acetoxypregnene; M. P. 244246- C.

Four hundred milligrams of A -3,11,2O-t1'ik6'tO-17oz-hY- droxy-2l-acetoxy-pregnene is dissolved in 50 cc. of glacial acetic acid containing three drops of 30% hydrobrornic acid in glacial acetic acid, and to the stirred solution is added a solution containing 0.61 ml. bromine (190 mg.) in 5 ml. of glacial acetic acid over a ten minute period. Five minutes after the addition of bromine is completed, the reaction mixture is poured into 400 ml. of ice Water, and the aqueous mixture is extracted three times with chloroform. The chloroform extracts are combined, Washed with aqueous sodium bicarbonate solution, then with water, dried and evaporated to dryness in vacuo to give A 4 bromo 3,11,20 triketo 17a hydroxy-Zlacetoxy-pregnene.

Five hundred milligrams of A -4-bromo-3,11,20-triketo- 17a-hydroxy-21-acetoxy-pregnene is heated under reflux with ml. of collidine for one hour; the reaction mixture is cooled and, with stirring, is treated with 35 m1. of a 2 N aqueous solution of sulfuric acid. The aqueous mixture is extracted three times with chloroform, and the combined chloroform extracts are dried and the chloroform evaporated therefrom in vacuo. The residual material is dissolved in benzene and chromatographed over g. of acid-Washed alumina. The chromatogram is eluted with mixtures of ether and chloroform, and the combined eluates are evaporated to dryness. The residual crystalline material is recrystallized from ethyl acetate to give substantially pure A -3,11,20-triketo-17ahydroxy-Zl-acetoxy-pregnadiene; M. P. 226228 C.

One hundred milligrams of A -3,11,20-triketo-17a,2ldihydroxy-pregnadiene 21-acetate is dissolved in a mixture of 1.0 cc. of benzene and 1.0 cc. of 1.1 N methanolic potassium hydroxide, and the solution is allowed to stand at room temperature for a period of about 10 minutes. The solution is then acidified with acetic acid, the henzene is evaporated in vacuo, and the residual material is recrystallized from ethyl acetate to give substantially pure A 3,11,20 triketo 17u,21 dihydroxy pregnadiene; M. P. 207-214 C.

Example 2 A solution of 500 mg. of A -3,20-diketc-11,17,21-trihydroxy-pregnadiene in ml. of methanol containing 5 drops of glacial acetic acid is mixed with a solution of 540 mg. of cupric acetate hydrate in ml. of methanol.

The mixture is heated under reflux for a period of about v triketo-l7a,2l-clihydroxy-pregnadiene, 0.5 part of anhydrous sodium acetate, 0.62 part of semicarbazide hydrochloride and 35 parts of 95% ethanol is heated at a temperature of about C. for about three hours. The reaction mixture is evaporated to small volume in vacuo, the concentrated solution is diluted with water, and the insoluble material which precipitates is recovered by fil- V tration, washed with Water and dried. The resulting material is purified by recrystallization from alcohol to pro- 4- duce substantially pure A -3,1l,20-triketo-17a,2l-dihydroxy-pregnadiene 3,20-bis-semicarbazone. A solution of 0.45 part of A -3,11,20-triketo-17a,21-dihydroxypregnadiene 3,20-bis-semicarbazone, 0.17 part of sodium borohydride, 9 parts of tetrahydrofuran and 3 parts of water is maintained at reflux temperature for approximately one hour. The reaction solution is cooled to about 15 C., and the excess sodium borohydride decomposed by the addition of a solution of 0.27 part of glacial acetic acid in 1.2 parts of water. The tetrahy-- drofuran is evaporated in vacuo, and the residual material is extracted with ethyl acetate. The extracts are Washed with a saturated salt solution, Water, 5% aqueous sodium bicarbonate solution and again with water. The extracts are dried and the ethyl acetate evaporated in vacuo to give A -3,20-diketo-115,17a,21-trihydroxypregnadiene 3,20-bis-semicarbazone. The A -3,20-di keto-l 1/3,17a,2l-trihydroxy-pregnadiene 3,20-bis-semicarbazone is mixed with 5 parts of glacial acetic acid, 1.5 parts of Water, 0.85 part of sodium acetate, and 0.8 part of 90% pyruvic acid, and the resulting mixture is heated under nitrogen for four hours at about C. The reaction mixture is diluted with 20 parts of Water, and the aqueous mixture is evaporated nearly to dryness in vacuo. The residualmaterial is triturated with Water and the organic material is extracted with ethyl acetate. The ethyl acetate solution is Washed neutral, dried, decolorized, and evaporated to small volume. Upon cooling the resulting concentrate, a crystalline material separates which is recovered by filtration and purified by recrystallization from ethyl acetate to give substantially pure A 3,20 diketo 11fi,17a,21 trihydroxy pregnadiene.

Example3 A fluoro 3,11,20 triketo 17a hydroxypregnadiene 21-aldehyde is prepared utilizing the procedure of Example 1, but using A -9oc-fill010-3,11,2O- triketo-17,2l-dihydroxy-pregnadiene as the starting material in place of the retrocortin utilized in Example 1.

The A 9a fluoro 3,11,20 triketo 17a,21 dihydroxy-pregnadiene used as. starting material in this example may be prepared in accordance with the procedure described hereinabove for preparing retrocortin, but using as stating material, instead of the 3,1l,20-triketo-17ahydroxy-2l-acetoxy-pregnane used in that procedure, the

. known compound 9a-fiuoro3,11,20-triketo-17a-hydroxy- The filtered solution is diluted with about 50 N the spirit and scope thereof.

21-acetoxy-pregnane.

Example 4 A 90c fluoro 3,20 diketo 11 8,1711 dihydroxypregnadiene 21-aldehyde is prepared utilizing the procedure of Example 2, but using A -9a-fiuoro-3,ZO-diketol1,8,17,2l-trihydroxy-pregnadiene as the starting ma terial in place of the hydro-retrocortin utilized in Example 2.

The 11 9a fluoro 3,20 diketo l1B,17a,21 trihydroxy-pregnadiene used as starting material in this example may be prepared in accordance with the procedure described hereinabove for preparing hydro-retrocortin, but usirn as starting material, instead of the retrocortin used in that procedure, the 9-fluoro-retrocortin prepared hereinabove.

Various changes and modifications may be made in carrying out the present invention without departing from Insofar as these changes and modifications are Within the purview of the annexed claims, they are to be considered as part of this invention.

I claim:

l. The process which comprises reacting A -3,20- diketo 9 (Y) l1 (R)'-17a,2l-dihydroxy-pregnadiene wherein Y is a radical selected from the group consisting of hydrogen and'halo radicals, and R is a radical selected from the group consisting of keto and hydroxy, with cupr1c acetate to produce the corresponding A -3,20-diketo 9-(Y)-1l-(R)-17u-hydroxy-pregnadiene 21 aldehyde.

2. The process which comprises reacting A -3,11,20- triketo-17a,2l-dihydroxy-pregnadiene with cupric acetate in a liquid medium comprising a polar solvent to produce AV -3,1 l,ZO-triketo-l7a-hydroXy-pregnadiene 2l-aldehyde.

3. The process which comprises reacting A -3,20-diketo-11B,l7a,2l-trihydroxy-pregnadiene with cupric acetate in a liquid medium comprising a polar solvent to produce A -3,20-diketo-1 1,8,17a-dihydroxy-pregnadiene 21-aldehyde.

4. The process which comprises reacting 9-halo-A 3,11,ZO-triketo-17a,2l-dihydroxy-pregnadiene with cupric acetate in a liquid medium comprising a polar solvent to produce 9-halo-A -3 ,1 1 ,ZO-triketo-17a-hydroxy-pregnadiene 21-aldehyde.

5. The process which comprises reacting 9-fluoro-A 3,11,20-triketo-17a,2l-dihydroxy-pregnadieue with cupric acetate in a liquid medium comprising a polar solvent to produce 9-flu0r0-A -3,11,20-triketo-l7a-hydroxypregnadiene 21-aldehyde.

6. The process which comprises reacting 9-halo-A 3,20-diketo-1 1B,1711,21-trihydroxy-pregnadiene with cupric acetate in a liquid medium comprising a polar solvent to produce 9-halo-A -3,20-diketo-11/3,17adihydroxypregnadiene 21-aldehyde.

7. The process which comprises reacting 9-fiuor0-A 3,20-diketo-l1/3,17a,2l-trihydroxy-pregnadiene with cupric acetate in a liquid medium comprising a polar solvent to produce 9-fiuoro-A -3,20-diketo-1lfl,l7a-dihydroxypregnadiene 21-aldehyde.

8. A A -3,20-diketo-9-(Y)-11-(R)-17a-hydroxy-pregnadiene 2l-aldehyde wherein Y is selected from the group consisting of hydrogen and halo radicals, and R is selected from the group consisting of hydroxy and keto radicals.

6 -9. 1,4-pregnadiene-17a-ol-3,20-dione-21-al of the for- 10. A -3,11,20-triketo-17a-hydroxy-pregnadiene 21-aldehyde.

11. A -3,20-diketo-11,3,17a-dihydroxy-pregnadiene 21- aldehyde.

12. 9 halo A 3,11,20 triketo 17a hydroxypregnadiene 21-aldehyde.

13. 9 fluoro A 3,11,20 triketo 17a hydroxypregnadiene 21-aldehyde.

14. 9 halo A 3,20 diketo 11,8,17a dihydroxypregnadiene 21-aldehyde.

15. 9 fiuoro A 3,20 diketo 11fl,17a dihydroxypregnadiene 21-aldehyde.

References Cited in the file of this patent UNITED STATES PATENTS 2,579,479 Djerassi Dec. 25, 1951 2,773,077 Conbere Dec. 4, 1956 2,773,078 Weijlard Dec. 4, 1956 OTHER REFERENCES Rogers: Jour. Am. Chem. Soc., 74, 2947 (1952). Fried: Jom'. Am. Chem. Soc., 75, 2273-74 (1953); 76, 1455 (1954). 

9. 1,4-PREGNADIENE-17A-OL-3,20-DIONE-21-AL OF THE FORMULA: 